Improvement of GPS DOP Variants with NavIC Constellation for Indian Users

Abstract

GPS, a standardized and matured satellite based navigation system, having a broad range of applications. It is widely preferred due to its fast and better performances. The accuracy of a GPS system is an important issue in PNT service to all the dependents, which is limited by geometry of visible satellites. With the advent of multiple constellations, research work is continuing to combine different constellations to get good geometry i.e. Dilution of Precision (DOP). In this research work, GPS and NavIC (Navigation Indian Constellation) constellations are combined to investigate the DOP values for the receiver located at GPCET (15.790N, 78.070E), Kurnool, India. GDOP is an instructional parameter as it specifies error in 3D position and time. In urban environments the GPS or NavIC users would be able to pick the satellite signals of higher elevation because of the obstructed sky view. In case of higher elevation mask angle (300) mean GDOP is 19.22 by GPS alone and 3.44 by the combined constellation (GPS+NavIC). Hence, the combination of GPS and NavIC is more preferable to get good geometry to improve the accuracy of PNT services in and around Indian region.